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Beagle 2 Failure Theories
Dan East writes "New Scientist has an article discussing the failure of ESA's Beagle 2 Lander. Theories as to why the landing failed include thinner than expected upper atmosphere, extreme atmospheric temperature fluctuations, and possible physical damage to Beagle 2 seen in an image acquired immediately after it separated from Mars Express. Recent data acquired by Mars Express, as well as NASA's Mars Rovers, are helping direct investigations into the failure. So far only around half of Beagle 2's landing ellipse has been imaged in an attempt to locate remnants of the lander. USA Today is also running an AP story on these latest theories."
Ok, this questions is *always* a popular one when talking about rovers on mars, and the solar panels that tag along with them. The reason that the panels can't use wipers to wipe the dust of is because the dust is electrostatically charged. Using the wipers would scratch the hell out of the panels, making them usually for gathering any more photons.
-brandon
It appears that dust covering the solar panels is only one of a number of factors which will end up rendering the mars rover a paperweight.
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The dust on the solar panels appears to be complicated by the fact that the batteries "lose capactity" and (probably most importantly) the sun moves past the latitude where the rover is located. Just like days get shorter in the winter...
I guess it doesn't matter if your solar panels are clean if they aren't being exposed to the sun for an appreciable length of time.
All of this was grossly overinterpreted from an article lean on details... http://marsrovers.jpl.nasa.gov/mission/tl_surface
NASA addressed this during the launch. They tried a lot of different methods of wiping the solar panels and found out it just wasn't cost effective to make something that would work. It added a ton of bulk and was prone to breakage. Hope that helps.
Tim Smith - Ramblings from Nerd Land
They did think about it. But it wouldn't be practical, or worth it.
It's actually a FAQ.
I suggest you read
This
and this
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Roses are #FF0000, Violets are #0000FF, find / -name '*base*' |xargs chown -R us && mv zig greatjustice
The Beagle2 lander was a small part of the overall mission. It was the result of an opportunity ('scuse the pun)later in the Mars Express project to tack an extra mission onto the mission platform. The process of obtaining detailed imaging of the surface of Mars is far, far more than "nothing to show for it except for failure." Have a look at the ESA page about the mission for more information.
Dialectician. Archology.
CNN has the scoop.
--- Hindsight is 20/20, but walking backwards is not the answer.
http://www.cnn.com/2004/TECH/space/03/08/mars.beag le.reut/index.html
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Possible sighting of Beagle probe
Monday, March 8, 2004 Posted: 6:43 PM EST (2343 GMT)
LONDON, England (Reuters) -- Beagle 2, the British space probe which disappeared as it descended towards Mars, may have been spotted on the surface of the Red Planet, scientists say.
No signal has been received from the craft since it was due to land on Christmas Day last year, despite various attempts by Mars orbiters and telescopes on Earth to make contact.
But photographic images of the area where Beagle 2 was to have come down show four bright spots, dubbed a "string of pearls" by scientists, which may be the remains of the probe.
"It could be the lander with its air bags and parachute," said Lutz Richter from the German Aerospace Center, who helped plan the Beagle 2 project as part of Europe's first solo mission to another planet.
(1) In Formula-1 racing, the helmets have visors that are covered with clear plastic tear-off sheets. Instead of wiping their visor if they get dirt on it while they're in the middle of a race, they just tear off the topmost sheet and they're good to go
This might be a viable option -- but then again it's possible that the sheets could tear or jam in such a way as to produce a high degree of reflection and significantly reduced array efficiency. It's just another point of failure.
(2) Pick the dust up. They make simple electrostatic floor cleaning brushes here on earth (as seen on TV) that pick up dust like nobody's business
Possible -- but it would also require the creation of a high-voltage charge -- and the other sensitive electronics onboard may not like that kind of charge. The high levels of ionizing radiation on the surface of Mars may also affect the operation of such devices.
(4) Gently blow atmospheric air across them. Small motor, high speed fan, nozzle directing the air across the surface. Probably won't work well on Mars with the thin atmosphere
Wouldn't even work on earth with its comparitively dense atmosphere. Haven't you noticed that even if you take a dusty car for a high-speed run at 100mph or greater, it's still covered in dust when you stop? Do a google on "boundary layer" and "laminar flow" to find out why this method won't work with very small dust particles.
(5) The system that deploys the solar panels could be designed so that the action of deploying them passes the panels past the cleaning apparatus. This, of course, favors designs that have the panels slide open - or unroll as with the international space station
It would not be a good idea to fold and unfold the panels any more than is absolutely necessary (ie: do it only once). Even the best-designed mechanism always suffers the possibility of jamming when used in a very dusty environment -- especially if there's also a high degree of thermal cycling. From memory, at least one of the planetary probes lost the use of a camera (or was it an antenna array?) due to such jamming. To open and close the solar arrays on a regular schedule would significantly increase the probability of failure and that failure would likely be catastrophic to the mission.
I don't understand how people are complaining about how the batteries are slowly decaying or that the solar day length is decreasing with the onset of winter. If it even takes three days to recharge in the winter - and you can only do 1/2 the work in a regular day: you'd still have a working probe as opposed to not having a working probe. If it can survive long enough, you'd get around to summer again
I suspect that the extremely low temperatures encountered on Mars would fatally damage the battery packs if they weren't kept warm. Once the amount of energy available during the martian winter day falls below the level required to maintain the battery temperature overnight -- the cells would be irreversibly damaged.
My Li-Ion cell phone battery has been discharged and recharged hundreds of times over the course of four years - and it still holds a usable charge. I thought that airgel was supposed to solve the temperature problem for the electronics (they can easily build spacecraft where the internal temperature of the electronics is maintained at whatever you want)
There is no such thing as "perfect" insulation so energy has to be expended overnight to keep the critical components (batteries, etc) from being damaged by freezing. As mentioned above, once the energy extracted during the daytime becomes insufficient to provide this heat -- the mission is over.
'reversing the polarity' usually only works in Star Trek :)
The problem with such measures is that you will need some kind of special coating on top of the panels (either anti-static, or conducting to hold the charge) and that is going to result in less efficient panels.
Jeroen
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